Mesofauna - Protura. Diplura. Pseudoscorpiones (Chapter II, Diversity of Soil Organisms)

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Soils are increasingly under pressure and

so are the organisms living in them.

Intensive agriculture, loss of aboveground

biodiversity, soil erosion and land degradation

are among the most relevant threats to soil

life. We can protect soil creatures by taking

specific actions. No-tillage, diversification of

crops, increasing reforestation and greater

use of natural amendments are examples of

interventions that may promote life in soils.

People need to know about the fascinating

world belowground and understand its value.

The Global Soil Biodiversity Atlas presents

the often neglected protagonists in the

environment that surrounds us all.

Soil is an extremely complex system

resulting from the essential interactions

between inert and living components.

Soils host a myriad of soil organisms ranging in

size from a few micrometres to

several centimetres, from the

microscopic bacteria and archaea to

the “giant” earthworms and moles.

All these organisms are distributed

over space and time, and each ecosystem

and season has its unique soil community.

Soil organisms interact to provide

essential ecosystem services to human beings

and the environment, ranging from supporting

plant growth to the regulation of climate.

SOIL BIODIVERSITY

ATLAS

GLOBAL

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Soil biodiversity is the variability among organisms living in soils.

The images above, from top left to bottom right, show representatives of the main groups of soil-dwelling organisms. Fungi, together with bacteria and archaea, are microorganisms. (BJ)

Nematodes, together with protists, tardigrades and rotifers, are microfauna. (AM)

Collembolans, together with mites, enchytraeids, proturans, diplurans and pseudoscorpions, are mesofauna. (AM) Earthworms, together with ants, termites, arachnids, isopods and myriapods, are macrofauna. (MK)

Soils sustain life and are full of life. (MT)

What is soil biodiversity? How does it vary in space and time? What does it provide to society?

What are the main threats to soil biodiversity? What can we do to preserve it?

The first ever Global Soil Biodiversity Atlas uses informative texts,

stunning photographs and striking maps to answer and explain these

and other questions.

Going through its nine chapters, every reader will learn what soils are

and about the amazing creatures living in them.

You will discover the factors influencing the distribution of soil organisms,

how soil biodiversity supports food production, the pressures affecting

soil life and the possible interventions to preserve it.

The Global Soil Biodiversity Atlas is an essential reference to understand

and appreciate the incredible world living under our feet.

LB-NA-27236-EN-N

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Supporting the EU Biodiversity Strategy and the Global Soil Biodiversity Initiative: preserving

soil organisms through sustainable land management practices and environmental policies for

the protection and enhancement of ecosystem services

SOIL BIODIVERSITY

ATLAS

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Global Soil Biodiversity Atlas | PREFACE

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The citation for this document is:

Orgiazzi, A., Bardgett, R.D., Barrios, E., Behan-Pelletier, V., Briones, M.J.I., Chotte, J-L., De Deyn, G.B., Eggleton, P., Fierer, N., Fraser, T., Hedlund, K., Jeffery, S., Johnson, N.C., Jones, A., Kandeler, E., Kaneko, N., Lavelle, P., Lemanceau, P., Miko, L., Montanarella, L., Moreira, F.M.S., Ramirez, K.S., Scheu, S., Singh, B.K., Six, J., van der Putten, W.H., Wall, D.H. (Eds.), 2016, Global Soil Biodiversity Atlas. European Commission, Publications Office of the European Union, Luxembourg. 176 pp. © European Union, 2016

Reproduction authorised for the sole purpose of teaching or scientific research, provided the source is acknowledged.

Published by the Publications Office of the European Union, L-2995 Luxembourg, Luxembourg.

EUR 27236 EN — Global Soil Biodiversity Atlas Printed version

ISBN 978-92-79-48169-7 ISSN 1018-5593 doi:10.2788/799182

Catalogue number: LB-NA-27236-EN-C

Online version

ISBN 978-92-79-48168-0 ISSN 1831-9424 doi:10.2788/2613

Catalogue number: LB-NA-27236-EN-N

2016–176 pp.–30.1 x 42.4 cm

Printed in Luxembourg.

Printed on elemental chlorine-free bleached paper (ECF).

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Legal Notice

Neither the European Commission nor any person acting on behalf of the Commission is responsible for the use that might be made of the following information.

Cartographic Representations

Underlying cartographic features depicted on the maps in this atlas are derived from the Digital Chart of the World and Lovell Johns Cartographic Base. These data do not have any explicit legal status; hence, no legal aspects should be derived from the information depicted on any of the maps in this publication.

http://en.wikipedia.org/wiki/Digital_Chart_of_the_World www.lovelljohns.com

Soil biodiversity data

Some of the maps of the atlas were previously published in scientific journals. Related references are clearly reported in the legends. The data and information to redraw the maps were obtained directly from the authors of the publications. Their usage for other purposes is not allowed. Copyright of original maps is as follows:

Cover image and graphics credits

The illustration on the front cover was created by Ian Dewsbery from Lovell Johns Ltd (UK) based on an idea of Alberto Orgiazzi and Arwyn Jones from the Joint Research Centre.

The images on the back cover were obtained from: Andy Murray (AM)

Brandon Jackson (BJ) Michael Kilner (MK) Mike Atkins (MT)

All these people and many of the contributors listed in ‘Images and graphic credits’ on the next page, were contacted through the Flickr website: www.flickr.com

The use of images contained in the atlas for educational, scientific and awareness raising purposes is allowed providing they are accompanied by a reference to the Atlas and the name of the original provider (see page 3).

The authors are very grateful for the incredible willingness and kindness of all people in providing their permission to use their images for the atlas.

Texts on the back cover by Alberto Orgiazzi and Arwyn Jones.

Final design and graphical support by Lovell Johns Limited, 10 Hanborough Business Park, Long Hanborough, Witney, Oxfordshire, OX29 8RU, United Kingdom.

www.lovelljohns.com

The authors are grateful for the incredible flexibility, understanding and high professional standards of Ian Dewsbery at Lovell Johns Ltd (UK) throughout the sometimes tortuous process of assembling this publication. Thanks also to Bernard Jenkins of the EU Publications Office for his assistance in coordinating the printing process.

DISCLAIMER

The European Commission has taken considerable care in preparing the information which is displayed in this atlas. At the scale of mapping presented in this atlas, political boundaries are only indicative. The European Commission assumes no responsibility or liability for any injury, loss or damage incurred as a result of any use of or reliance upon the information and material contained in this atlas.

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CHAPTER II – DIVERSITY OF SOIL ORGANISMS | Global Soil Biodiversity Atlas

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20 µm

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Morphology

Proturans are small soil-inhabiting primitive hexapods (ranging in size from 0.5 and 2.5 mm – see page 31) with no antennae and no eyes. The forelegs are used as sensory organs; they have many sensory organs (‘sensilla’) covering their posterior segments (tarsi). On the dorsal side of the head there are a pair of other important sensory organs (pseudoculi) whose functions are not well understood. Their bodies are cylindrical, pointed at both ends and generally unpigmented, pale or yellowish. Similar to the Collembola, they are wingless arthropods and their mouthparts are entognathous, meaning that they are retracted within the head capsule: the mandibles and maxillae are slender and their maxillary palps (mouthparts) are long, with setae and sensilla. They are born with nine abdominal segments and grow by successive moultings during which they add new distal segments. The adult has 12 abdominal segments. They have small pairs of lateral-ventral appendages on the first three abdominal segments. They lack cerci, the paired appendages on the rear-most segment of the body present in many other hexapods. Reproduction occurs with indirect fertilisation: the males deposit packets of sperm (spermatophores) and the females collect the spermatophores. [55, 56]

Taxonomy

The class Protura (phylum Arthropoda, subphylum Hexapoda) includes three orders: Acerentomata (families Hesperentomidae, Protentomidae and Acerentomidae), Sinentomata (families Fujientomide and Sinentomidae) and Eosentomata (families Eosentomidae and Antelientomidae).

Microhabitat

Protura are found in moist soils, leaf litter, humus, moss and decaying wood in woodland, grassland and agricultural soils. They do not thrive in very acid soils (e.g. coniferous woodlands). Usually, they are part of the decomposer community and help break down organic matter in soil and litter. In particular, proturans feed mainly on fungal hyphae (see box, page 39), but they are also important prey for small predators, such as spiders, mites (see page 49) and pseudoscorpions (see page 53).

Diversity, abundance and biomass

Proturans are found all over the world, with the exception of the polar regions. There are more than 700 described species. Their density is variable in relation to the characteristics of the soil and the content of organic matter. In disturbed and degraded soils they can be completely absent, while in undisturbed habitats, such as natural grasslands, there can be as many as 85 000 individuals per square metre.

Mesofauna – Protura

• Among hexapods (see page 31), Protura was the last class to be described. The first description of these minute soil arthropods was given in 1907.

• Filippo Silvestri and Antonio Berlese, two Italian entomologists, discovered proturans independently.

• The first species to be described was Acerentomon doderoi, found in soil near Syracuse, New York, USA.

• When disturbed, proturans seem to raise the end of the abdomen in a defensive posture similar to that adopted by scorpions.

The ‘young’ proturans

Morphological structures of the proturan Acerentomon italicum: (a) the

sensory organs, sensilla and setae, on the exterior side of the legs; (b)

pseudoculi, the eye-like structures that are not actually eyes, on the dorsal side of the head; (c) the mouthparts are entognathous, meaning that they

are retracted within the head. (LGA)

(a) and (c) Proturans in their natural environment in New Zealand and the UK, respectively. Proturans live

mainly in soil, mosses and leaf litter in moist temperate forests. (b) Scanning electron microphotograph

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Global Soil Biodiversity Atlas | CHAPTER II – DIVERSITY OF SOIL ORGANISMS

52 a

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Morphology

Diplura are small wingless hexapods (see page 31), with body lengths ranging from 0.3 to 1 cm, although the largest species can be longer than 2 cm. Diplurans have a narrow and elongated body, and are generally white or colourless. The head has a pair of long and moniliform (a string formed of bead-like segments) antennae and no eyes. The abdomen ends with a pair of cerci, i.e. prominent abdominal appendages, which can contain silk glands. The cerci can have either a pair of pincers (Japygoidea) or can be filamentous (Campodeoidea). Some species of japygid Diplura are robust and darker in colour, and are often confused with earwigs (Dermaptera – see box to the right). However, Diplura have neither eyes nor wings. Fertilisation is similar to that found in proturans and collembolans (see pages 50-51): the males produce and deposit a large number of spermatophores, capsules containing spermatozoa, on the substrate that are then picked up by a female. The females lay eggs in clumps in the soil cavities or decomposing vegetation. Some species check the eggs and the larvae. Diplura are known to be able to regenerate lost body parts, such as legs, antennae and cerci. [57, 58]

Taxonomy

The class Diplura (phylum Arthropoda, superclass Hexapoda) comprises nine extant families, the main ones being Japygidae and Campodeidae (each with more than 400 species).

Microhabitat

Diplura live in wood, leaf litter, under stones, rocks or logs, on the surface of, or in deeper layers of soil, in mosses or in termite and ant nests. Many species are herbivores and detritivores (feed on decomposing plant and animal parts) and feed on a wide range of plant material. However, some species have well-developed mandibles and eat nematodes (see pages 46-47), small arthropods, enchytraeids (see page 48), etc. They can also consume fungal mycelia (see box on page 39) and plant detritus. They are often part of the decomposer community, helping recycle dead plant material.

Diversity, abundance and biomass

There are approximately 1 000 described species that are common inhabitants of most natural and human modified soils. They are distributed worldwide, from the tropics to temperate zones. They do not have specific habitat preferences and, generally, their population densities are not high (< 50 individuals per square metre).

Mesofauna – Diplura

• Male diplurans produce large numbers of spermatophores (up to 200 per week), probably because sperm only remain viable in the spermatophore for about two days.

• The eggs of campodeid and japygid diplurans are normally laid in a mass of up to 40, in clumps or on small stalks in little cracks or cavities in the ground.

• Female campodeid diplurans abandon their eggs, but japygid species are known to remain in the brood chamber with the egg cluster, protecting the eggs and the newborn larvae.

• Some diplurans in the Japygidae family may be occasionally confused with earwigs. This confusion is due to the presence in both groups of pincer-like abdominal appendages, scientifically known as cerci.

• Diplurans are not insects. Earwigs are insects of the order Dermaptera and live in similar habitats: moist places beneath stones, boards, sidewalks, debris or in the soil. • The forcep-like appendages, i.e. cerci, of some diplurans are designed to break off

near the base if they are mishandled. This behaviour is probably an anti-predatory adaptation. It is known as autotomy and is typical also of reptiles, such as lizards, and amphibians, such as salamanders. Diplurans are among the few terrestrial arthropods known to be able to regenerate lost body parts (legs, antennae and cerci) over the course of several moults.

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Diplurans are not earwigs

Maternal care of diplura

Despite having similar forcep-like structures, (a) earwigs and

(b) japygid diplurans are very distinct animals. (MH, KSC)

Detail of the pincer-like stuctures of the dipluran Catajapyx aquilonaris belonging to the family of Japygidae. These abdominal appendages are scientifically known as cerci. (NS)

Campodeidae diplurans. (a) A live specimen shows the typical shape of this group. They are pale, eyeless

hexapods and have two long abdominal appendages and antennae. (b) A live specimen of Campodea augens

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CHAPTER II – DIVERSITY OF SOIL ORGANISMS | Global Soil Biodiversity Atlas

53 a

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Morphology

Pseudoscorpions are tiny arachnids known as ‘false scorpions’ because they look similar to scorpions but do not have an elongated postabdomen with a venomous sting at the end. Usually less that 5 mm in length, they are brownish arachnids with large pincer-like chela (pedipalps). The body is divided in two regions: the cephalothorax (or prosoma, a fused head and thorax) and the abdomen (or opisthosoma) clearly divided into 11 - 12 segments. The cephalothorax is covered dorsally by a shield (carapace) and bears the appendages. One to two pairs of simple eyes (ocelli) are sometimes present on the head, but many species are blind. The first pair of cephalic appendages, the chelicerae, are two-segmented, chelate (clawed) and used for feeding. Chelicerae have silk glands. Behind the chelicerae are the pedipalps, which are used to capture prey and for defence. Pseudoscorpions, like all arachnids, have four pairs of thoracic legs. The abdomen has no appendages. These animals have a long lifecycle (the course of developmental changes through which an organism passes from its birth to the mature state in which it may give birth to another organism), depending on the environment and the temperature. The males produce a spermatophore, and pull the female over it. The female carries a silken egg bag of about 12 - 40 eggs in a brood sac that is attached to the ventral surface of the opisthosma. She can produce several broods each year. The young pseudoscorpions moult, passing from several larval instars (protonymph, deutonymph and tritonymph) before becoming adults that can live three to four years. [59]

Taxonomy

The Pseudoscorpionida or Pseudoscorpiones is a large group comprising 27 different families. They are found everywhere, but their highest diversity is found in the tropics.

Microhabitat

Pseudoscorpions live under bark and stones, in leaf litter, in caves, under rocks on the ground and in soil. They are also often found in moss and lichens, in ant and bee nests and in the burrows of ground-dwelling mammals. The cosmopolitan species Chelifer

cancroides is often found in houses. Diversity, abundance and biomass

Approximately 3 400 species of Pseudoscorpions have been described. Their density, in general, is not high (< 300 individuals per square metre). In some cases they are considered beneficial to humans as they prey on various pest species; for example, carpet beetle larvae, ants, mites and booklice. Occasionally Pseudoscorpiones may disperse attached to flying insects, birds and mammals (phoresy).

Mesofauna – Pseudoscorpionida

• The dispersion of the tropical American pseudoscorpion

Cordylochernes scorpioides from one tree to another is mediated

by the Harlequin beetle Acrocinus longimanus. The males show territorial behaviour on the back of the beetles and even mate with females there.

• Nesticus birsteini (today Carpathonesticus birsteini) distributed in Russia and Georgia, is the only pseudoscorpion to have appeared on a postage stamp.

A beetle for a house

Diversity of pseudoscorpions: (a) Chthonius delmastroi was described the first time in 2009 in Italy; (b) Rhacochelifer maculatus was discovered by the

famous entomologist and arachnologist Ludwig Carl Christian Koch in 1873; (c) Roncus sardous owes its name to the Italian island Sardinia where it

was first discovered; (d) Neobisium (Ommatoblothrus) zoiai belongs to a genus of pseudoscorpions which includes over 230 different species. (SZO)

Female pseudoscorpion carries its brood sac. (MY)

Detail of the cephalic appendages of a pseudoscorpion. The smaller ones (dark red) are called chelicerae; the bigger ones (pale red) are the pedipalps and have a defensive function. (AM)